A documented source for pointing to the Torah with the pinky

There is a very "popular" minhag that when the Sefer Torah is lifted up during hagbah, the whole congregation stands and points to it with their pinky. I had always assumed that there was no source for it, just something that developed over time. According to R'Ari Enkin of Hirhurim, that is in fact not the case. He points to the the Me'am Loez on Parshat Ki Tavo which if not the original source for the minhag, at least documents that this minhag is fairly old (The author of the Me'am Loez began writing in 1730 (from this Wiki article ). If anyone has the full text, could they please post it up into the comments. Many thanks.